MITSUBA HD7000 Nokia N95 Replacement Battery 3.7V 750mAh

MITSUBA HD7000 / HDC505 Series — 3.7V Li-ion Replacement Battery

This is a 3.7V Li-ion cell rated at 750mAh (2.78Wh), built to the same form factor as the original battery in the Nokia N95 8GB and compatible HD7000 / HDC505 / Protax DC500T platforms. The N95 8GB runs a power-hungry load — simultaneous GPS lock, 5MP camera processing, and 3G radio — so a worn original cell shows its limits fast. This replacement slots in at the same 53.49 × 33.44 × 6.91mm footprint with no case modification.

• HD7000, HDC505, HDC-505, Protax DC500T fit: These models share the same cell dimensions, 3.7V nominal voltage rail, and connector pinout. The BMS handshake on each platform reads the same charge termination voltage, so one cell spec covers the full group without a firmware conflict.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the N95 8GB platform. The BMS accepted the new cell without triggering an overvoltage flag, and charge termination landed at the correct 4.2V cutoff on the first cycle.
• Fuel gauge recalibration on first use: Disable the N95 8GB's automatic screen brightness and GPS on first use, then run one full discharge-to-charge cycle uninterrupted. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before normal mixed-load use begins.

Why the N95 8GB reports wrong battery percentage after a cell swap

The N95 8GB uses a fuel gauge IC that stores a discharge curve calibrated to the original cell. When a new cell goes in, the IC is still referencing the old cell's impedance and capacity profile. The percentage shown on screen is calculated against that stale curve, so the reading drifts — often reading higher than actual early in discharge and then dropping suddenly. One full uninterrupted discharge-to-charge cycle forces the IC to rewrite its reference points against the new cell, bringing reported percentage back into alignment.

Sudden shutdown at 20–30% remaining on a replacement cell

This happens when the combined load of the 3G modem, GPS chip, and screen backlighting pulls enough current to cause a momentary voltage sag the BMS interprets as a low-cell event. A new cell with an uncalibrated fuel gauge makes this worse — the IC hasn't learned the cell's actual sag curve yet, so it misjudges the cutoff threshold. The fix is the same calibration cycle: discharge fully until the phone shuts itself off from true depletion, then charge uninterrupted to 100%. After that single cycle, the BMS cutoff triggers at the correct voltage — around 3.4V under load rather than early.